That sounds like a "starting tap" -- one of a set of three, the other two being a "plug tap" and a "bottoming tap".
I don't know for sure, but I got the impression that he was tapping a fairly shallow blind hole, which calls for a plug tap to start with, and a bottoming tap to finish up with.
Given that the workpiece is hardened, I suspect that a carbon steel tap would be too brittle for the task (and this may be what he got). I would consider one of HSS (High Speed Steel) to be more durable in this task.
And, my preference for most tapping, including hand tapping, is one designed for machine tapping -- the spiral tip or "gun tap", which can be good (without frequent reversing) until you get too close to the bottom of the hole, at which point a bottoming tap is still required in a blind hole. The gun tap is even better for a through hole, as it chases the chips ahead of it and does not require the frequent reverals to break chips that normal hand taps require.
Enjoy, DoN.